Ariana Grande has sung Crowded House's 'Don't Dream It's Over' with Miley Cyrus at her benefit concert, in defiance against the terrorists who killed 22 people at her concert in Manchester just a fortnight ago.

The pair have performed the New Zealand band's hit before, but the Kiwi anthem carried renewed poignance after the tragic bombing that occurred at Grande's concert in Manchester Arena last month.

"They come, they come, to build a wall between us - we know they won't win."

Before the song, Cyrus explained the history of their performance of the song and gave a touching tribute to her fellow pop star and friend.

"We've done this song together before when she came and joined me for the Backyard Sessions - we sang 'Don't Dream it's Over'.

"And I never knew I'd be sitting here with you today, so I'm happy to share this time with my friend. You've always been there for me and now I'm happy to be there for you, and be here with all of you guys," she said, gesturing to the crowd."

"We haven't done this one in a while, but we're gonna sing it, and we hope y'all sing along too."

Earlier, concert-goers joined Robbie Williams in an adapted rendition of his single 'Strong' that celebrated the city's mettle in the face of adversity.

Other acts performing at the concert include Justin Bieber, Coldplay, Katy Perry and Miley Cyrus and more for the One Love show at the Manchester's Old Trafford Cricket Ground.